The manufacture of protective articles, such as apparel, requires the use of one of many different materials depending upon the specific threat which the apparel is designed to protect against. One of the common uses for protective apparel is to provide cut and puncture resistance from knives and other sharp instruments. Protective apparel is also commonly used to shield the wearer against excessive heat or flame which can cause severe burn injury. Likewise, protective apparel is also commonly used to insulate the wearer against excessive cold or wind which can cause severe hypothermia or frost bite injury. Furthermore, protective apparel is also useful in protecting workers from the harmful effects of electromagnetic energy (such as is emitted from wireless communication devices), chemical exposure, abrasion, repetitive motion injury, blunt instrument trauma, and cumulative trauma injury from exposure to, for example, vibration.
Over the years, those skilled in the art have designed a substantial number of protective garments to protect workers against these, and other, threats of injury. Each of the prior protective garments, however, was developed to counter a particular threat. For example, cut-resistant gloves were developed to protect a wearer's hand from cuts inflicted by sharp surfaces such as knife blades. These same gloves, however, provide little or no protection from other threats of injury such as excessive temperatures, electromagnetic energy emissions, chemical exposure, abrasion, repetitive motion injury, blunt instrument trauma and cumulative trauma from exposure to, for example, vibration.
Workers are often exposed simultaneously to multiple threats of injury while on the job. A common example occurs in the meat processing industry where a worker is exposed simultaneously to sharp instruments, extremely cold temperatures and harmful chemicals. To counteract each of these threats of injury, a worker typically wears three different pairs of gloves, each pair to protect against a different threat of injury. The first pair, for example, may be liner gloves to keep the hands warm. Gloves made of a cut-resistant material may then be worn over the liner gloves to guard against cuts from the sharp instruments used in meat processing operations. Finally, gloves made of a waterproof material are frequently worn over the cut-resistant gloves to keep the worker's hands dry and free from exposure to the harmful chemicals used in meat processing operations.
Another problem that is encountered with protective apparel designed to counteract a single threat of injury is that generally a heavy weight fabric must be used to obtain a higher degree of protection from threats such as fire or laceration. While offering more protection, apparel made from a heavier fabric typically lacks tactile sensitivity, and thus can impede the worker's ability to properly perform a required task. Consequently, it is very common for workers who are provided with protective garments made from a heavier fabric to avoid using the protective apparel because it restricts the freedom of movement necessary for them to accomplish the tasks they are required to perform. For example, surgeons and other medical personnel infrequently use cut-resistant liner gloves despite the availability of such gloves since the late 1980's. Instead, they elect to forego the protection from cuts afforded by such gloves because the protective garments made from existing cut-resistant materials impair tactile sensitivity and limit manual dexterity. This decision is consciously made on a daily basis by these individuals despite their full knowledge of the serious health risks presented by blood-borne pathogens.
Another common problem is that protective apparel which is designed to protect a worker from one particular threat of injury, is often used in applications requiring protection from a different or multiple threats of injury. Frequently, consumers of protective apparel select a product which addresses their most troublesome safety concern. In doing so, however, they sacrifice safety in one or more other areas of concern. As a consequence workers are left unprotected, or underprotected, from the dangers associated with these secondary safety concerns.
For example, in the meat processing industry, workers are required to wear cut-resistant apparel due to the extremely sharp cutting instruments used in meat cutting operations. Among other garments, meat processing workers utilize cut-resistant gloves and cut-resistant sleeves to protect themselves from being injured by the sharp cutting instruments. Over the past several years, the trend in the meat processing industry has been to substitute lightweight cut-resistant materials for the high performance cut-resistant materials previously utilized to reduce fatigue and repetitive motion injury caused by the use of heavy gloves and sleeves. The lightweight materials also improve the tactile sensitivity of the gloves. The consequence of this substitution, however, has been a reduction in the degree of cut resistance provided by the protective apparel. Thus, an improvement in the secondary characteristics of the protective apparel has been made at the expense of the primary objective of the apparel to overcome lesser problems that are inherent with the particular application.
While the above example is intended to point out the most obvious failure of the state of the art protective apparel, there is a yet a greater and more common failure. In many industries or work-related activities that are not as closely regulated, workers consciously choose to not wear protective apparel of any kind because the available protective garments create difficulties which the workers perceive are greater than the threat of injury that the garment was designed to overcome. Simply put, if a worker cannot effectively and efficiently perform the tasks required of him because of a restriction introduced by a protective garment, he is likely to elect to forego the benefit of the protective garment altogether.
There are many other reasons why workers and other individuals do not utilize conventional protective apparel. Among these are:
(a) Overheating. In certain work environments, an individual can become overheated when wearing existing protective apparel designed to counteract a particular threat of injury which requires the use of a heavy weight fabric. Naturally, if a worker is uncomfortable wearing a protective garment, he will frequently forego the use of the garment. This is particularly true if the garment is being worn over a large area of the body to protect only a relatively small area, such as the use of a glove to protect the tip of only one finger of the hand.
(b) Fatigue and repetitive motion injury. As previously discussed, conventional protective apparel made of a heavy weight fabric is often rigid and therefore interferes with the freedom of movement of the worker. This impediment to free motion hinders the worker's ability to perform tasks which require dexterity. The rigid fabric may also cause premature fatigue and, worse yet, injury due to repetitive motion. The weight of certain articles of existing protective apparel tends to have a detrimental effect on the worker's endurance, particularly when worn over an extended period of time, such as the entire work shift.
(c) Costs. Employers and self-employed individuals frequently find cost to be a prohibitive factor when deciding whether to buy an expensive protective garment that protects a relatively large area of the body, particularly when only an isolated area of the body requires protection. Brick masons are an excellent example of this phenomenon. A brick mason generally wears out only three areas of protection on a conventional cut-resistant glove; namely, the tip of the thumb, index finger, and middle finger on the hand that handles the bricks. The rest of the glove is merely excess material that is simply thrown away when these areas become worn. This excess material, however, can also be unnecessarily hot and uncomfortable for the wearer.
(d) Inherent material dangers. Frequently, the desirable attributes of a particular protective material are the same attributes that are hazardous or unfavorable to the user. For example, protective apparel having exceptionally high abrasion resistance are often made of a thermoplastic material, such as polyethylene, polypropylene or polyester, and thus also have exceptionally smooth or slippery surfaces. Protective garments made of such thermoplastic materials are often rejected by workers whose jobs require manual dexterity because the slippery surfaces of the garments frequently cause the worker to drop items that he is handling, thus creating spoilage and additional hazards in the work place. Such thermoplastic materials may also have a relatively low melting point, and thus can melt in the presence of accidental exposure to high temperatures or flame. Polyethylene melts at approximately 300.degree. F. and polyester melts at less than about 600.degree. F. Thus, both melt below the temperature generally produced by combustion of flammable materials. When a burn trauma occurs to an individual wearing protective apparel made of these materials, the severity of the burn is often exacerbated by the melting of the material utilized to make the protective garment.
To date, manufacturers of protective apparel have approached resolving the above mentioned problems with primitive techniques that have resulted in limited success. One approach has been to sacrifice the level of performance of the apparel by substituting materials that are less effective for the particular threat of injury, but which avoid the exposure to other threats of injury that are inherent in using the optimum materials for the particular threat. Another approach has been to manufacture protective articles from multiple materials pieced together The lack of success experienced in manufacturing "customized" protective apparel for particular applications is exemplified by the following:
Common work, or chore, gloves for use in gardening, farming and other activities requiring tactile sensitivity and a high degree of abrasion resistance are manufactured by a process that involves multiple steps of creating separate fabrics of different materials and joining the fabrics together, along with a cuff material, to form the glove. The resulting "composite" glove includes the attributes necessary to satisfy all of the threats of injury presented by such activities. The uppermost, or digit portion of the glove, is typically formed of an aramid fabric, such as an ultra high molecular weight extended chain polyethylene, to provide the tactile sensitivity necessary to perform tasks requiring manual dexterity. The central, or palm, portion of the glove is typically formed of a canvas fabric or leather and is sewn to the lower edge of the digit portion of the glove. The canvas fabric or leather of the palm portion provides a good gripping surface which is somewhat abrasion resistant. The lowermost, or cuff, portion of the glove is typically formed of an elastic material and is sewn to the lower edge of the palm portion of the glove. The cuff portion is made of an elastic material to conform tightly to the wrist of the wearer so as to prevent soil or contaminants, such as oil, from coming into contact with the skin on the wearer's hand.
While the above described construction addresses the multiple threats of injury present in a particular application, manufacture of such protective apparel is both labor intensive and costly, and the resulting gloves are heavy and uncomfortable to wear. Further, protective apparel of this type typically undergoes evolutions of development which generally result in the manufacturer sacrificing performance of a given attribute to enhance performance of another attribute. In the particular example given herein, sacrifices are generally made in ductile sensitivity, abrasion resistance and comfort to enhance rigidity, cut resistance and resistance to extreme temperatures and chemicals, thereby resulting in a heavy and cumbersome glove. A worker is less likely, however, to wear gloves that are heavy, uncomfortable and are not optimized to address the particular threat of injury which the worker most often encounters. Thus, the worker is left unprotected, or is left underprotected when he in fact does wear the gloves.
The examples discussed herein are merely a summary of the problems exhibited by the current state of the protective apparel art. Obviously, numerous considerations must be addressed and overcome to produce both functional and optimum protective apparel for a particular application. Thus, a need clearly exists for protective articles made of a composite fabric that provide an unprecedented level of safety and comfort, and for a continuous, one-step process for manufacturing protective articles made of a composite fabric.